Wind turbine blades are generally constructed by the formation of first and second blade shells by the layup and subsequent infusion with resin of fibre material, e.g. glass fibre and/or carbon fibre, in a suitably shaped mould. The blade shells, which are usually shaped to form complimentary pressure- and suction-side profiles of a wind turbine blade, can then be joined together along the leading and trailing edges of the shells to form a wind turbine blade, through the application of a structural adhesive between the edges of the shells.
One of the known construction techniques for wind turbine blades is the use of sandwich panel constructions in the blade body. In such blades, the shell of the wind turbine blade comprises sections wherein a lightweight core material of e.g. balsawood or foam is located between inner and outer layers of fibre-reinforced material. The use of such a construction provides a relatively cheap and lightweight structure having increased stiffness and buckling resistance, compared to a shell formed from fibre-reinforced material alone.
One of the continued challenges in wind turbine blade manufacture is the development of wind turbine blades having increased resistance to blade buckling, in particular between the blade shear webs and the trailing edge of the blade. Proposed systems include improving the placement of the structural adhesive at the blade trailing edge, to provide a relatively strong bond between blade shells. However, such solutions can result in an increased quantity of structural adhesive used in the blade, which can accordingly increase the cost and weight of the final blade. U.S. Pat. No. 8,047,800 describes a solution wherein an excess of structural adhesive is applied between the trailing edges of a pair of blade shells, but which requires the use of a special tool to draw out excess adhesive through the trailing edge gap between the blade shells prior to curing.
It is an object of the invention to provide a wind turbine blade with improved structural bonding, and an associated method of manufacture.